Network Working Group D. Heagerty
Request for Comments: 1670 CERN
Category: Informational August 1994
Input to IPng Engineering Considerations
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
This document was submitted to the IETF IPng area in response to RFC
1550. Publication of this document does not imply acceptance by the
IPng area of any ideas expressed within. Comments should be
submitted to the big-internet@munnari.oz.au mailing list.
Summary
This white paper expresses some personal opinions on IPng engineering
considerations, based on experience with DECnet Phase V transition.
It suggests breaking down the IPng decisions and transition tasks
into smaller parts so they can be tackled early by the relevant
experts.
Timescales
In order to allow key decisions to be taken early, I would like to
see IPng decisions and timescales broken down into into smaller
parts, for example:
- address structure and allocation mechanism
- name service changes
- host software and programming interface changes
- routing protocol changes
Although interrelated, not all details need to be defined by the same
date. Identify which decisions will be hard to change and which can
be allowed to evolve. All changes should be worked on in parallel,
but the above list indicates a feeling for urgency of a decision.
Our experience has been that administrative changes (as may be
required for addressing changes) need the greatest elapse time for
implementation, whereas routing protocol changes need the least.
Heagerty [Page 1]
RFC 1670 Input to IPng Engineering Considerations August 1994
I would like to see an early decision on address structure and enough
information for service managers to start planning their transition.
Some hosts will never be upgraded and will need to be phased out or
configured with reduced connectivity. A lead time of 10 years (or
more) will help to take good long term technical decisions and ease
financial and organisational constraints.
Transition and deployment
Transition requires intimate knowledge of the environment (financial,
political as well as technical). The task needs to be broken down so
that service managers close to their clients can take decisions and
make them happen.
Let the service managers adapt the solutions for their environment by
providing them with a transition toolbox and scenarios of their uses
based on real examples. Clearly state the merits and limitations of
different transition strategies.
Provide for transition autonomy. Let systems and sites transition at
different times, as convenient for them.
Identify what software needs to be changed and keep an up-to-date
list.
Identify what is essential to have in place so that service managers
can transition at their own pace.
Allow for a feedback loop to improve software based on experience.
Configuration, Administration, Operation
We run IP on a wide range of equipment and operating systems. We
need an easy way to (re-)configure all our IP capable systems. The
systems need to be sent their IP parameters (e.g., their address,
address of their default router, address of their local name servers)
and we need to obtain data from the system (e.g., contact information
for owner, location and name of system). We also need an easy way to
update DNS.
In our environment systems are regularly moved between buildings and
we therefore find the tight coupling of IP address to physical subnet
over restrictive. Automatic configuration could help overcome this.
We would like to efficiently load balance users of various IP based
services (e.g., telnet, ftp, locally written applications) across a
number of systems.
Heagerty [Page 2]
RFC 1670 Input to IPng Engineering Considerations August 1994
The ability to break down addresses and routing into several levels
of hierarchy is important to allow the delegation of network
management into subdomains. As the network grows so does the desire
to increase the number of levels of hierarchy.
Disclaimer and acknowledgments
This is a personal view and does not necessarily represent that of my
employer. I have benefited from many transition discussions with my
colleagues at CERN, other High Energy Physics DECnet managers and
Digital Equipment Corporation engineers.
Security Considerations
Security issues are not discussed in this memo.
Author's Address
Denise Heagerty
Communications Systems Group
Computing and Networks Division
CERN
European Laboratory for Particle Physics
1211 Geneva 23, Switzerland
Phone: +41 22 767-4975
Fax: +41 22 767-7155
EMail: denise@dxcoms.cern.ch
Heagerty [Page 3]